Multiplying calculator, including a slidable slate



C. LlPKlN Dec. 22, 1953 MULTIPLYING CALCULATOR, INCLUDING A SLIDABLE SLATE v 2 Sheets-Sheet l Filed April 20, 1951 INVENTOR. CHARLES LIPK 1N Dec. 22, 1953 c. LIPKIN.

MULTIPLYING CALCULATOR, INCLUDING A SLIDABLE SLATE Filed April 20. 1951 JOLL 2 Sheets-Sheet 2 VH l mwa :SMHIIIJ I@ ,8 VHHHllm/ll VNI 25? Il Z5 7. 5M/Z Vmm mslm Hulman' l@ f8 :7 FZ5.

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INVENTOR. CHARLES LLPKm Patented Dec. 22, 1953 MULTIPLYING CALCULATOR, INCLUDING A SLIDABLE SLATE charles Lipkin, New York, N. Y. Application April 20, 1951, Serial No. 222,059

8 Claims. 1

This invention relates to new and useful improvements in indicating devices for assisting in multiplication of two numbers.

More particularly, the present invention relates to an aid for carrying out multiplication, of simple and novel construction and operation using the principle of slide multiplication whereby any number or figure may be quickly multiplied by any other number or iigure and the product quickly and accurately obtained.

One object of the present invention is to provide a device which superflcially resembles a slide rule but in reality is an indicating device adapted to be used in conjunction with the sliding method of multiplying numbers.

Another object of the present invention is to take advantage of the obvious utility found in the common magic slate and to combine forms thereof with an indicating device adapted tc be used in conjunction with the sliding method of multiplying numbers.

A further object of the present invention is to provide with an indicating device adapted to bev used in conjunction with the sliding method of multiplying numbers and including magic slates upon which'numbers are erasably indicated, novel means effective for facilitatedly erasu ing said numbers from the magic slates.

Another object 4of the present invention is to provide in an indicating device adapted to be used in Vconjunction with the sliding method of multiplying numbers, a stationary magic'slate divided into a plurality of boxes for having the numbers of a multiplicand indicated therein, a sliding magic slate also divided into ak plurality of boxes for having the numbers of a multiplier indicated therein, and a stationary magic slate divided into a vplurality of boxes sufficient in number for indicating the product of the multiplier and multiplicand.

Another object of the present invention is -to provide in an indicating device adapted for aiding in the multiplication of numbers and'includ ing a pair of magic slates for indicating multi. plier and multiplicand and one of which is slidingly movable relative to the other, means effective for indicating when the said magic slates are properly positioned for commencing a multiplying operation.

Another object of the present invention is to provide in an indicating device employing magic slates, novel "magic slate arrangements which are facilitatedly attachable to the device and removable for being discarded and replaced.V

Still another object of the present Ainvention is to provide in a device including a slidable member and a stylus or similar marking implement, novel means whereby said stylus may be employed for locking the slidable member as to prevent sliding thereof and means forv assuring the retention of said stylus in its effective slide-locking position when such is desired.

For further comprehension of the invention, and of the objects and advantages thereof, reference will be had to the following description and accompanying drawings, and to the appended claims in which the various novel features of the invention are more particularly set forth.

In the accompanying drawings forming a matcrial part of this disclosure:

Fig. 1 is a plane view illustrating the invention.

Fig. 2 is a front side elevational view of the device.

Fig. 3 is a left-hand side elevational view.

Fig. 4 is an isometric view illustrating the B-slate and the slide to which it is ordinarily fastened.

Fig. 5 is a sectionalview taken along the lines 5 5 in Fig. 4.

Fig. 6 is a fragmentary broken away and enlarged isometric View illustrating the stylus retaining means.

Fig. 7 is a top plan and partially broken away view of a second embodiment of the invention.

Fig. is a sectional view taken along the lines the device of '8 8 in Fig. 7, but with the magic slates. reu

moved.

Figs. 9 through 15 are schematic illustrations showing the progressive movements of the B-slate during a multiplication operation.

Now with reference to the drawings in more detail, and particularly to Figs. 1, 2 and 3, it will be seen that the invention provides a frame if), comprising a basemember l i and a side block l2. Formed in the base member l i are first, second, and third undercut channels i3, lli and l5, respectively; and provided for being slidingly inserted therein are first, second, and third magic slates i6, l? and i8, respectively.

Shown in Figs. 4 and 5 is the construction of the third magic slate i3, the description of which will be sufficient for the understanding of all three. Secured together by staples le, or the like, and arranged superimposedly is an elongated first backing member 2B, a wax surfaced strip 2 i, a translucent strip 22, and a transparent strip 23. Arranged beneath the nrst backing member 2liv is a second backing member 2d. A strap member 25 having its extremities secured to the second trip 22 to n adhere to the Wax surfaced stripgiivhichfis v usually darkly colored.

In the present arrangement erasures, or tne stripping of the translucent strip from theivvax surfaced strip, are e'ected by thetstrap member; I

25 when the magic slate i8 is slidingly moved rightwardly with respect to the second backing member 2f; to which said strap member is anchored.

Now, with reference to Figs. 1 anda, it will be seen that both the first and third magic slates l and respectively, are equally divided into pluralities of indicating spaces or boxes 2E. Said spaces or boxes are formed by permanent vertical markings il which may be provided either on the translucent or transparent strips and 23, respectively. Also permanently marked in the right-handmost space 'in the nrst magic slate i5 is an asterisk or like marker 23. Similarlyr marked is the left-handmost one of the spaces 2e inthe third magic slate lil.

The second magic slate il is provided With vertical markings Z which divide it into a plurality of indicating spaces or boxes'i'i sufficient in number for indicating the digits oi the prod-V uct of the square of any factor indicated in the boxes of either the Vrst or third magic slate." There are twice as many boxes 3i] as boxest.

As best shown in Figs. 1 and e, all of the magic slates are provided at the extremities opposite the s rap members E5 with a tab il formed oil the second backing members 2d. 'The tubs 3i of the first and second magic slates are ladapted to be secured in the frame it by screws or the like 32 in the side block i2 and passing there-- through. This arrangement permits the magic slates"7 is and l? to be erased simply by slidingly pulling same outwardly from the channels it and iLl, respectively, while their related second backing members 2d, and therefore the strap members 25, are held relatively still. Y

Provided for being slidingly inserted in the third channel i5 beneath thel second backing member` of the third magic slate lil is` a slipy stick 33 which is best seen in Fig-fl. Aixed adjacent the left-hand end of the slip stick is a block A first step undercut in said` block 3d is adapted to receive the tab 3i of the third magic slate and a screw 36 is provided for securing same. A second step 3l undercut in the said block 3d is providedV orreceiving and holding down the left-hand extremity of the third magic slate i3. This arrangement permitsthe said third magic slate to move slidinglyin the channel i 5 With the slip stick 35i. A tab $55 formed off the left-hand end of said `slip stick 33 facilitates the holding of said slip stick while the magic slate is moved rightwardly and outwardly from the channel i5 to thereby eiect erasures of markings thereon.

As shown best in Figs. l, 2 and G, the present device is provided with a stylus for eecting markings on the several magicslatesi A passage 4G through the frame lil one wall oi which is formed in part by the slip stick block 3st is provided for both retaining said st; "us when not in use and for eiiecting locking or" the slip stick. A leaf spring having one end thereof imbedded in the base member l! disposed in the passage l-li, is ective ior i with and assuring the ret ntion ci the said stylus in sail'passage.

A second embodiment or the invention is in Figs. 'l and 3 and conter t e of a frame its made up oi three superimposed layers of'material and having a slip stick arranged slidingly between the iirst and third layers.V Arranged slidingly in the frame ita, are-nrst and'second magic and ila,

Strap members provided for the saine purpose as described above. in the present arrangement the ends of the strap member cooperating with the iirst and second magic slates i6 and i'ieextend into and secured in the Walls forming the associated channels in the frame lila, while the ends oi .thai-.one cooperating with the'third magic slate are secured in the Vsaid slip stick'. `Eor this purpose the sides of slip'stick are raised to forni a channel iorfslate illand the ends of strap for this slate are e bedded in said sides. Wi' h this arrangement it is possible to eliminate the second backing member 253 req'ulired in the construction of the Erst embodiment described above.

.e stylus 3de is provided foruse with this embodiment7 also, and when not in use stored'in a passage fiile in the mentionedframe ite.

New, the present invention in both of its shown embodiments may be considered a new form of indicating device whichv permits the answers to multiplication problems being readin significant figures, rather than in logarithmic scales which must be deciphered and which may have varying values.

In Vorder to explain the manner in which the device indicates and assistsiin the multiplication of a pair of numbers, a complete problem will be novvworked out as though it was being indicated on the magic slates of the first embodiment.

The problem is to multiply 2304 by 137, and as seen in Fig.v 9', either one of these factors be selected as the multiplica-nd and marked in the first magic slate i6 with the units digit in the space marked with the asterisk. Thereafter, the multiplier is marked in the third magic slate I8 in reverse and with the units digit thereof also located in the asterisk marked space.

Then, as shown in Fig. l, the third slate is moved slidingly to align vertically the asterisk marked spaces of the first and thiru slates. The aligned numbers are then multiplied to obtain the product of 7 times 4 which is 28. The 8 is marked in the rst space of the second magic slate il and the 2 is carried.

The third slate is then moved to the left to align the 7 With the 0 and the 3 with the 4 in the manner seen in Fig. l1. Again the vertically aligned numerals are multiplied and the sum of the products thereof plus the Apreviously carried 2 amounts to 14.- The 4 is marked in the next space of the second yslate and the l is carried.

Again, the third slate is moved, and in the position thereof seen in Fig. l2, the 7 is aligned vertically with the 3, the 3 With the il and the 1 lwith the 4, and again these aligned agceaocs' numerals are multiplied; Y rEhe sum of these products plus the; previously carried fi amount to 26. rIhe 6 is marked onthe second slate and the 2 is carried.

The just described procedure is repeated following progressive sliding movements of the third slate I8, which movements and the mannerA of marking the final product are clearly illustrated in the remaining Figs. 13, r14 and l5.

It will be understood that it is immaterial as to which of the factors is shown on either slate or which one thereof is marked reversedly.V Also,l for persons who find it difficult to remember the numbers to be carried, the boxes or spaces in which no computationsaretaking place may b e utilized f or marking down the carried numbers.

It is to be noted that the present device possesses the' advantage of V having the naifproduct marked down, which-'is -not found in slide rules or the like. Y, Y Y

While I have illustrated and described the preferr-ed embodimentsof my invention, it is to be understood that I do not limit myself to the precise constructions herein disclosed and the right is reserved to all changes and modifications coming Awithin the scope of the invention as defined in the appended claims.

Having thus described my invention, what I claim as new, and desire to secure by United States Letters Patent is:

l. In an indicating device of the class described for aiding in the multiplication of numbers; the combination of a frame member provided with three parallel channels, a stationary first magic slate disposed in a rst of said channels and divided as to provide a plurality of spaces for the indication of digits comprising a multiplicand; a stationary second magic slate disposed in a second of said channels and divided as to provide a plurality of spaces sufficient for the indication of a product; al third magic slate disposed in a third of said channels between the rst and second thereof and being similar to` the first `and for the indication of digits comprising a multiplier; and said third slate being slidingly movable relative to the others as to render any digit of the multiplier vertically alignable with any digit of the multiplicand.

2. In an indicating device of the class described for aiding in the multiplication of numbers; the combination of a frame member provided with three parallel channels, a stationary first magic slate disposed in a rst of said channels and divided as to provide -a plurality of spaces for the indication of digits comprising a multiplicand; a stationary second magic slate disposed in a sec- 0nd of said channels and divided as to provide a plurality of spaces suflicient for the indication of a product; a third magic slate disposed in a third of said channels between the first and second thereof and being similar to the first and for the indication of digits comprising a multiplier: and said third slate being slidingly movable relative to the others as to render any digit of the multiplier vertically alignable with any digit of the multiplicand, and said first and third magic slates each having markings to indicate the multiplier integer spaces and for being aligned vertically to assure the proper multiplication commencing positions of the said first and third magic slates.

3. In an indicating device of the class described for aiding in the multiplication of numbers; the combination of a frame member provided with three parallel channels, a stationary first magic slate disposed inafirst of said channels 'and mark'edas to provide a plurality of juxtaposed spaces for the'indication 'of digits comprising a multiplicand; 'ai stationaryV second magic slate disposed in fa second of said channels and marked as to provide a plurality of juxtaposed spaces sufficient for the indication of the digits of at least the square of said multiplicand; a third magic slate`disposed in a third of said channels between the rst and second thereof and being similar to the rst and for the indication of digits comprising a multiplier; and said third slate being slidingly movable relative to the others as to lrender any 'digit of the multiplier vertically alignable' with any number of the multiplicand.

4,.. In an 'indicatingdevice of the class described foraiding in the multiplication of numbers; the combination of a frame member provided with three parallel channels, a stationary first magic slate disposed in a first of said channels and `marked as to provide a plurality of juxtaposed spaces for the indication of digits comprising a multiplicand; a stationary second magic slate disposed in a second of said channels and marked as to provide a plurality of juxtaposed spaces sufficient for the indication of the digits of at least the square of said multiplicand; a third magic slate disposed in a third of said channels between the first and second thereof and being similar to the first and for the indication of digits comprising a multiplier; and said third slate being slidingly movable relative to the others as to render any digit of the multiplier vertically alignable with any number of the multiplicand, and the right and left-hand end ones of the spaces of the said first and third magic slate, respectively, having permanent markings to indicate the multiplier integer spaces and for being aligned vertically to assure the proper multiplication commencing positions of the said first and third "magic slates.

5. In a device, as set forth in claim 1, wherein each "magic slate comprises the superimposed arrangement of an elongated backing member, a wax surfaced strip, a translucent strip, and a transparent strip, all of which strips are secured at their extremities to said backing member; of spaced permanent markings on said translucent strip whereby the magic slate is divided into a plurality of juxtaposed data indicating spaces.

(i. In a device, as Set forth in claim 2, wherein each magic slate comprises the superimposed arrangement of an elongated backing member, a wax surfaced strip, a translucent strip, and a transparent strip, all of which strips are secured at their extremities to said backing member; of spaced permanent markings on said translucent strip whereby the magic slate is divided into a plurality of juxtaposed data indicating spaces, another elongated backing member; and a strap member secured at both ends to the second mentioned backing member and passing transversely between said wax surfaced and translucent strips, whereby markings caused by the adherence of said translucent strip to said waxed surface may be erased by slidingly moving the first mentioned backing member longitudinally relative to the said strap and the second mentioned backing member.

7. In an indicating device as set forth in claim 3, further including a slip sti-ck slidingly insertable in said third channel; the magic slate slidingly inserted in said third channel including a superimposed elongated arrangement of a backing member, a wax surfaced strip, a transa lueentstrip,Y and vva transparent strip, all of which are secured together'at'their extremities; another backingV member slidingly inserted in said thirdV channelbeneath the magic slate and secured to said slip stick; and a strap `member secured at itsendsto the seeond mentiened backing meinber 'passing transversely between said Wax surfaced and translueent strips,` whereby marl;- ings caused 2y adherence oi said translucent strip to saidV waxed surface may ne erased by slidingly moving the rst mentioned backing member outN Wardly from said channel whileflielding frmiy therein the said sip stick.

8. in anindicating device as set forth in claim 4, further eiuding a slip sticlrslidingly insertaele in sait. third channel; the magic slate siidingly inserted in said tiird. cnannelinciudng a superimnesedY elengate-d arrangement o1" a backing membrana W 'i suraeed strip, a transn lucent strip, a transparent strip, all of which are secured f together at their extremities; anot er leaekingmember siidingly insertedv in said third channel beneath the magic slate and secured to said slip stick; and a strap member,

secured at its ends to the second menti-onedbacking member and passing .transversely between said Wax surfaced and translucent strips, Whereby markings caused by adherence of said translucent strip to said .waxed surface may be erased slidingly moving the .rst mentioned backing member outwardly from said channel While holdingrmly .therein the saidslp stick; a mari; eiecting implement for use With the magic s1ates; and axially'alignable passages through saidy frame and ,.slip stick for maintaining said slip stick rlocked when the said implement is retained therein.

CHARLES LIPKIN.

Kaufman l June 17, 19497 

